The question is in the Practical Exercises for coastal navigation: It uses the Long Island Sound Chart #12354

Q: You have left Mattituck Inlet and passed close by the Green ATON 3A just to the North at 0900. You want to go to Clinton harbor to the NNE but want to ensure you leave the RG ATON TE Fl R (2+1) 6s to the East by exactly one mile. Your vessel speed through the water will be 6 knots. By consulting the tables you estimate the current will be 3 knots out of the east. Additionally, you estimate the leeway from windage will be 10 degrees to port. What should be your heading? What time will you pass by the ATON?

A:

To solve this draw the line from 3A to 1 nm west of the RG Aton. Now do a 1-hour plot. Draw the current vector 3nm from 3A to the west. Scribe a 6nm arc from the end of your current vector over the desired ground track. Where the scribe meets the ground track is where you will be in 1 hour. Draw a line from the end of the current vector to the scribe. This is your water track and non-leeway heading which is 43 deg T, 57 deg M. From the Deviation table the deviation will be 4 deg E

This will give a compass heading of

T 43

V 14 W

M 57

D 4 E

C 53

Now since your wind gives you 10 deg to port you should aim another 10 deg higher which is 63 deg.

Measure the distance from 3A to the scribe. It is 4.6 nm. Over 1 hour that is 4.6 knots. The distance to the Aton is 7.6 nm. At 4.6 knots it will take 1 hr 39 minutes.